Leaf for ledgers.



L. E. SHIPMAN.

LEAP FOR LEDGERS.

APPLIGATIOH FILED JAIL 20, 1906.

; PATENTED MAR. 6, 1906.

C LW

UNITED T ES PATENT OFFICE.

LESTER E. SHIPMAN, OF NEW YORK, N. Y., ASSIGNOR- TO ASA L. SHIPMANS SONS, OF NEW YORK, N. Y., A FIRM.

LEAF Fen LEDGERS.

7 Specification of Letters Patent.

Patented March 6, 1906.

Application filed January 20, 1905. Serial No. 241,924.

. vented a certain new and useful Im rovement in Leaves for Ledgers, of which t e following is a specification.

The invention relates to leaves constructed to lie'flat when the book composed of such leaves is openfor service, and more particularly to leaves of this character designed to serve inwhat are known as loose-leaf ledgers.

The invention is in that class in which the desired flexibility is secured b removing a ortion of the material from t e sheet in a ine or lines of eater or less width and length parallel with t e binding edge.

The object of the invention is to provide a leaf in which the desired flexibility is secured by such grooves and at the same time insure sufficient stren th to resist the strains to .which the leaf is subjected in use, and thus reduce the liability to tear along the groove.

The invention consists-in certain novel features by which the above objects are attained.

The accompanying drawings form a part of this specification and show a preferred form of-the invention. a

Figure 1 is a face view of a leaf containing my invention; and Fig. 2 is a section on the line 2 2 in Fi 1, showing, on a greatly-enlar ed scale, t e sha e of the grooves.

imilar letters of reference indicate the some portions in both the res. A is the body of the sheet, referably of goodqualit linen stock, and A are, the notches or s ots in the binding edge, by which the leaf may be secured in an of the usual or referre types of loose-lea binders;

B are the grooves extending the full hei ht of the sheet from top to bottom paralle with the binding edge. Two grooves are preferred, and sly-experiments indicate that each should be about one-half inch in Width and separated from each other by about the same distance. The grooves are sion and again sim produced hya cutting-wheel rotated at an extremely hi h velocity and having the cuttor-surface shaped to produce the contour shown in Fig. 2, in which it'will be noted all sharp rentering angles at the sides of the grooves'are omitted and the surface line of the sheet descends radually into the depresfiarly rises from the op 0- site side of the roove, as indicated at B joining the b0 y of the sheet by smoothlyrounded reverse curves. By eliminating the angles 1 am able to produces. roove of sufii cient depth to insure the fiexi ility required and at the same time avoid the formation of lines of weakness along which a tear is likely to develo under strain. Another element of strengt inheres by reason of the effect of the rapidly-moving cutting-surface in compacting the remaining fiber of the paper along the groove, due to the pressure of the cutter and also to the polishing eflect of the cutter-blades upon the surface of the groove, the latter show the same smooth hard surface as the calen ered portions of the sheet, as indicated at a a.

I prefer to treat one face of the sheet only and, as above stated, to produce two grooves of about the proportions shown for leaves for ledgers and analogous books of the usual sizes; but it will be understood that a greater or less number of grooves may be made and that the widths of the grooves'and of the s aces between them may be varied in accor ance with the size of the sheet and the conditions of the service for which it may be designed.

I am aware that sheets havi grooves or weakened portions, with the si es of such grooves at more or less sharp angles with the ott-om, extending from near the top to near the bottom of the sheet and also" the full height of the sheet with a lincof perfoliations therein and rooves formed by grinding awa y the material: have been before proposed and I do not claim such; but

What l do claim, and Letters Patent, is-

1% leaf of the character set forth, comprising a sheet having a groove extending across desire to secure by athc sheet near and parallel with the )indiug edge, said groove being formed by removin a portion of the material of the sheet, sai groove having a plane bottom line curved gradually upward therefrom and joined to 5 the main surface of the sheet b reverse curves, the de ressed surface of said groove being hardene and polished.

In testimony that I claim the invention above set forth I affix my signature in presence of two witnesses.

LESTER E. SHIPMAN. Witnesses CHAS. A. HAUCK, CHARLES R. SEARLE. 

